/*
 * Copyright (c) 2016, Alliance for Open Media. All rights reserved
 *
 * This source code is subject to the terms of the BSD 2 Clause License and
 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
 * was not distributed with this source code in the LICENSE file, you can
 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
 * Media Patent License 1.0 was not distributed with this source code in the
 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
 */

#include <arm_neon.h>
#include <assert.h>

#include "./aom_config.h"
#include "./av1_rtcd.h"
#include "aom_dsp/txfm_common.h"
#include "av1/common/common.h"

static INLINE void TRANSPOSE8X8(int16x8_t *q8s16, int16x8_t *q9s16,
                                int16x8_t *q10s16, int16x8_t *q11s16,
                                int16x8_t *q12s16, int16x8_t *q13s16,
                                int16x8_t *q14s16, int16x8_t *q15s16) {
  int16x4_t d16s16, d17s16, d18s16, d19s16, d20s16, d21s16, d22s16, d23s16;
  int16x4_t d24s16, d25s16, d26s16, d27s16, d28s16, d29s16, d30s16, d31s16;
  int32x4x2_t q0x2s32, q1x2s32, q2x2s32, q3x2s32;
  int16x8x2_t q0x2s16, q1x2s16, q2x2s16, q3x2s16;

  d16s16 = vget_low_s16(*q8s16);
  d17s16 = vget_high_s16(*q8s16);
  d18s16 = vget_low_s16(*q9s16);
  d19s16 = vget_high_s16(*q9s16);
  d20s16 = vget_low_s16(*q10s16);
  d21s16 = vget_high_s16(*q10s16);
  d22s16 = vget_low_s16(*q11s16);
  d23s16 = vget_high_s16(*q11s16);
  d24s16 = vget_low_s16(*q12s16);
  d25s16 = vget_high_s16(*q12s16);
  d26s16 = vget_low_s16(*q13s16);
  d27s16 = vget_high_s16(*q13s16);
  d28s16 = vget_low_s16(*q14s16);
  d29s16 = vget_high_s16(*q14s16);
  d30s16 = vget_low_s16(*q15s16);
  d31s16 = vget_high_s16(*q15s16);

  *q8s16 = vcombine_s16(d16s16, d24s16);   // vswp d17, d24
  *q9s16 = vcombine_s16(d18s16, d26s16);   // vswp d19, d26
  *q10s16 = vcombine_s16(d20s16, d28s16);  // vswp d21, d28
  *q11s16 = vcombine_s16(d22s16, d30s16);  // vswp d23, d30
  *q12s16 = vcombine_s16(d17s16, d25s16);
  *q13s16 = vcombine_s16(d19s16, d27s16);
  *q14s16 = vcombine_s16(d21s16, d29s16);
  *q15s16 = vcombine_s16(d23s16, d31s16);

  q0x2s32 =
      vtrnq_s32(vreinterpretq_s32_s16(*q8s16), vreinterpretq_s32_s16(*q10s16));
  q1x2s32 =
      vtrnq_s32(vreinterpretq_s32_s16(*q9s16), vreinterpretq_s32_s16(*q11s16));
  q2x2s32 =
      vtrnq_s32(vreinterpretq_s32_s16(*q12s16), vreinterpretq_s32_s16(*q14s16));
  q3x2s32 =
      vtrnq_s32(vreinterpretq_s32_s16(*q13s16), vreinterpretq_s32_s16(*q15s16));

  q0x2s16 = vtrnq_s16(vreinterpretq_s16_s32(q0x2s32.val[0]),   // q8
                      vreinterpretq_s16_s32(q1x2s32.val[0]));  // q9
  q1x2s16 = vtrnq_s16(vreinterpretq_s16_s32(q0x2s32.val[1]),   // q10
                      vreinterpretq_s16_s32(q1x2s32.val[1]));  // q11
  q2x2s16 = vtrnq_s16(vreinterpretq_s16_s32(q2x2s32.val[0]),   // q12
                      vreinterpretq_s16_s32(q3x2s32.val[0]));  // q13
  q3x2s16 = vtrnq_s16(vreinterpretq_s16_s32(q2x2s32.val[1]),   // q14
                      vreinterpretq_s16_s32(q3x2s32.val[1]));  // q15

  *q8s16 = q0x2s16.val[0];
  *q9s16 = q0x2s16.val[1];
  *q10s16 = q1x2s16.val[0];
  *q11s16 = q1x2s16.val[1];
  *q12s16 = q2x2s16.val[0];
  *q13s16 = q2x2s16.val[1];
  *q14s16 = q3x2s16.val[0];
  *q15s16 = q3x2s16.val[1];
  return;
}

static INLINE void IDCT8x8_1D(int16x8_t *q8s16, int16x8_t *q9s16,
                              int16x8_t *q10s16, int16x8_t *q11s16,
                              int16x8_t *q12s16, int16x8_t *q13s16,
                              int16x8_t *q14s16, int16x8_t *q15s16) {
  int16x4_t d0s16, d1s16, d2s16, d3s16;
  int16x4_t d8s16, d9s16, d10s16, d11s16, d12s16, d13s16, d14s16, d15s16;
  int16x4_t d16s16, d17s16, d18s16, d19s16, d20s16, d21s16, d22s16, d23s16;
  int16x4_t d24s16, d25s16, d26s16, d27s16, d28s16, d29s16, d30s16, d31s16;
  int16x8_t q0s16, q1s16, q2s16, q3s16, q4s16, q5s16, q6s16, q7s16;
  int32x4_t q2s32, q3s32, q5s32, q6s32, q8s32, q9s32;
  int32x4_t q10s32, q11s32, q12s32, q13s32, q15s32;

  d0s16 = vdup_n_s16((int16_t)cospi_28_64);
  d1s16 = vdup_n_s16((int16_t)cospi_4_64);
  d2s16 = vdup_n_s16((int16_t)cospi_12_64);
  d3s16 = vdup_n_s16((int16_t)cospi_20_64);

  d16s16 = vget_low_s16(*q8s16);
  d17s16 = vget_high_s16(*q8s16);
  d18s16 = vget_low_s16(*q9s16);
  d19s16 = vget_high_s16(*q9s16);
  d20s16 = vget_low_s16(*q10s16);
  d21s16 = vget_high_s16(*q10s16);
  d22s16 = vget_low_s16(*q11s16);
  d23s16 = vget_high_s16(*q11s16);
  d24s16 = vget_low_s16(*q12s16);
  d25s16 = vget_high_s16(*q12s16);
  d26s16 = vget_low_s16(*q13s16);
  d27s16 = vget_high_s16(*q13s16);
  d28s16 = vget_low_s16(*q14s16);
  d29s16 = vget_high_s16(*q14s16);
  d30s16 = vget_low_s16(*q15s16);
  d31s16 = vget_high_s16(*q15s16);

  q2s32 = vmull_s16(d18s16, d0s16);
  q3s32 = vmull_s16(d19s16, d0s16);
  q5s32 = vmull_s16(d26s16, d2s16);
  q6s32 = vmull_s16(d27s16, d2s16);

  q2s32 = vmlsl_s16(q2s32, d30s16, d1s16);
  q3s32 = vmlsl_s16(q3s32, d31s16, d1s16);
  q5s32 = vmlsl_s16(q5s32, d22s16, d3s16);
  q6s32 = vmlsl_s16(q6s32, d23s16, d3s16);

  d8s16 = vqrshrn_n_s32(q2s32, 14);
  d9s16 = vqrshrn_n_s32(q3s32, 14);
  d10s16 = vqrshrn_n_s32(q5s32, 14);
  d11s16 = vqrshrn_n_s32(q6s32, 14);
  q4s16 = vcombine_s16(d8s16, d9s16);
  q5s16 = vcombine_s16(d10s16, d11s16);

  q2s32 = vmull_s16(d18s16, d1s16);
  q3s32 = vmull_s16(d19s16, d1s16);
  q9s32 = vmull_s16(d26s16, d3s16);
  q13s32 = vmull_s16(d27s16, d3s16);

  q2s32 = vmlal_s16(q2s32, d30s16, d0s16);
  q3s32 = vmlal_s16(q3s32, d31s16, d0s16);
  q9s32 = vmlal_s16(q9s32, d22s16, d2s16);
  q13s32 = vmlal_s16(q13s32, d23s16, d2s16);

  d14s16 = vqrshrn_n_s32(q2s32, 14);
  d15s16 = vqrshrn_n_s32(q3s32, 14);
  d12s16 = vqrshrn_n_s32(q9s32, 14);
  d13s16 = vqrshrn_n_s32(q13s32, 14);
  q6s16 = vcombine_s16(d12s16, d13s16);
  q7s16 = vcombine_s16(d14s16, d15s16);

  d0s16 = vdup_n_s16((int16_t)cospi_16_64);

  q2s32 = vmull_s16(d16s16, d0s16);
  q3s32 = vmull_s16(d17s16, d0s16);
  q13s32 = vmull_s16(d16s16, d0s16);
  q15s32 = vmull_s16(d17s16, d0s16);

  q2s32 = vmlal_s16(q2s32, d24s16, d0s16);
  q3s32 = vmlal_s16(q3s32, d25s16, d0s16);
  q13s32 = vmlsl_s16(q13s32, d24s16, d0s16);
  q15s32 = vmlsl_s16(q15s32, d25s16, d0s16);

  d0s16 = vdup_n_s16((int16_t)cospi_24_64);
  d1s16 = vdup_n_s16((int16_t)cospi_8_64);

  d18s16 = vqrshrn_n_s32(q2s32, 14);
  d19s16 = vqrshrn_n_s32(q3s32, 14);
  d22s16 = vqrshrn_n_s32(q13s32, 14);
  d23s16 = vqrshrn_n_s32(q15s32, 14);
  *q9s16 = vcombine_s16(d18s16, d19s16);
  *q11s16 = vcombine_s16(d22s16, d23s16);

  q2s32 = vmull_s16(d20s16, d0s16);
  q3s32 = vmull_s16(d21s16, d0s16);
  q8s32 = vmull_s16(d20s16, d1s16);
  q12s32 = vmull_s16(d21s16, d1s16);

  q2s32 = vmlsl_s16(q2s32, d28s16, d1s16);
  q3s32 = vmlsl_s16(q3s32, d29s16, d1s16);
  q8s32 = vmlal_s16(q8s32, d28s16, d0s16);
  q12s32 = vmlal_s16(q12s32, d29s16, d0s16);

  d26s16 = vqrshrn_n_s32(q2s32, 14);
  d27s16 = vqrshrn_n_s32(q3s32, 14);
  d30s16 = vqrshrn_n_s32(q8s32, 14);
  d31s16 = vqrshrn_n_s32(q12s32, 14);
  *q13s16 = vcombine_s16(d26s16, d27s16);
  *q15s16 = vcombine_s16(d30s16, d31s16);

  q0s16 = vaddq_s16(*q9s16, *q15s16);
  q1s16 = vaddq_s16(*q11s16, *q13s16);
  q2s16 = vsubq_s16(*q11s16, *q13s16);
  q3s16 = vsubq_s16(*q9s16, *q15s16);

  *q13s16 = vsubq_s16(q4s16, q5s16);
  q4s16 = vaddq_s16(q4s16, q5s16);
  *q14s16 = vsubq_s16(q7s16, q6s16);
  q7s16 = vaddq_s16(q7s16, q6s16);
  d26s16 = vget_low_s16(*q13s16);
  d27s16 = vget_high_s16(*q13s16);
  d28s16 = vget_low_s16(*q14s16);
  d29s16 = vget_high_s16(*q14s16);

  d16s16 = vdup_n_s16((int16_t)cospi_16_64);

  q9s32 = vmull_s16(d28s16, d16s16);
  q10s32 = vmull_s16(d29s16, d16s16);
  q11s32 = vmull_s16(d28s16, d16s16);
  q12s32 = vmull_s16(d29s16, d16s16);

  q9s32 = vmlsl_s16(q9s32, d26s16, d16s16);
  q10s32 = vmlsl_s16(q10s32, d27s16, d16s16);
  q11s32 = vmlal_s16(q11s32, d26s16, d16s16);
  q12s32 = vmlal_s16(q12s32, d27s16, d16s16);

  d10s16 = vqrshrn_n_s32(q9s32, 14);
  d11s16 = vqrshrn_n_s32(q10s32, 14);
  d12s16 = vqrshrn_n_s32(q11s32, 14);
  d13s16 = vqrshrn_n_s32(q12s32, 14);
  q5s16 = vcombine_s16(d10s16, d11s16);
  q6s16 = vcombine_s16(d12s16, d13s16);

  *q8s16 = vaddq_s16(q0s16, q7s16);
  *q9s16 = vaddq_s16(q1s16, q6s16);
  *q10s16 = vaddq_s16(q2s16, q5s16);
  *q11s16 = vaddq_s16(q3s16, q4s16);
  *q12s16 = vsubq_s16(q3s16, q4s16);
  *q13s16 = vsubq_s16(q2s16, q5s16);
  *q14s16 = vsubq_s16(q1s16, q6s16);
  *q15s16 = vsubq_s16(q0s16, q7s16);
  return;
}

static INLINE void IADST8X8_1D(int16x8_t *q8s16, int16x8_t *q9s16,
                               int16x8_t *q10s16, int16x8_t *q11s16,
                               int16x8_t *q12s16, int16x8_t *q13s16,
                               int16x8_t *q14s16, int16x8_t *q15s16) {
  int16x4_t d0s16, d1s16, d2s16, d3s16, d4s16, d5s16, d6s16, d7s16;
  int16x4_t d8s16, d9s16, d10s16, d11s16, d12s16, d13s16, d14s16, d15s16;
  int16x4_t d16s16, d17s16, d18s16, d19s16, d20s16, d21s16, d22s16, d23s16;
  int16x4_t d24s16, d25s16, d26s16, d27s16, d28s16, d29s16, d30s16, d31s16;
  int16x8_t q2s16, q4s16, q5s16, q6s16;
  int32x4_t q0s32, q1s32, q2s32, q3s32, q4s32, q5s32, q6s32, q7s32, q8s32;
  int32x4_t q9s32, q10s32, q11s32, q12s32, q13s32, q14s32, q15s32;

  d16s16 = vget_low_s16(*q8s16);
  d17s16 = vget_high_s16(*q8s16);
  d18s16 = vget_low_s16(*q9s16);
  d19s16 = vget_high_s16(*q9s16);
  d20s16 = vget_low_s16(*q10s16);
  d21s16 = vget_high_s16(*q10s16);
  d22s16 = vget_low_s16(*q11s16);
  d23s16 = vget_high_s16(*q11s16);
  d24s16 = vget_low_s16(*q12s16);
  d25s16 = vget_high_s16(*q12s16);
  d26s16 = vget_low_s16(*q13s16);
  d27s16 = vget_high_s16(*q13s16);
  d28s16 = vget_low_s16(*q14s16);
  d29s16 = vget_high_s16(*q14s16);
  d30s16 = vget_low_s16(*q15s16);
  d31s16 = vget_high_s16(*q15s16);

  d14s16 = vdup_n_s16((int16_t)cospi_2_64);
  d15s16 = vdup_n_s16((int16_t)cospi_30_64);

  q1s32 = vmull_s16(d30s16, d14s16);
  q2s32 = vmull_s16(d31s16, d14s16);
  q3s32 = vmull_s16(d30s16, d15s16);
  q4s32 = vmull_s16(d31s16, d15s16);

  d30s16 = vdup_n_s16((int16_t)cospi_18_64);
  d31s16 = vdup_n_s16((int16_t)cospi_14_64);

  q1s32 = vmlal_s16(q1s32, d16s16, d15s16);
  q2s32 = vmlal_s16(q2s32, d17s16, d15s16);
  q3s32 = vmlsl_s16(q3s32, d16s16, d14s16);
  q4s32 = vmlsl_s16(q4s32, d17s16, d14s16);

  q5s32 = vmull_s16(d22s16, d30s16);
  q6s32 = vmull_s16(d23s16, d30s16);
  q7s32 = vmull_s16(d22s16, d31s16);
  q8s32 = vmull_s16(d23s16, d31s16);

  q5s32 = vmlal_s16(q5s32, d24s16, d31s16);
  q6s32 = vmlal_s16(q6s32, d25s16, d31s16);
  q7s32 = vmlsl_s16(q7s32, d24s16, d30s16);
  q8s32 = vmlsl_s16(q8s32, d25s16, d30s16);

  q11s32 = vaddq_s32(q1s32, q5s32);
  q12s32 = vaddq_s32(q2s32, q6s32);
  q1s32 = vsubq_s32(q1s32, q5s32);
  q2s32 = vsubq_s32(q2s32, q6s32);

  d22s16 = vqrshrn_n_s32(q11s32, 14);
  d23s16 = vqrshrn_n_s32(q12s32, 14);
  *q11s16 = vcombine_s16(d22s16, d23s16);

  q12s32 = vaddq_s32(q3s32, q7s32);
  q15s32 = vaddq_s32(q4s32, q8s32);
  q3s32 = vsubq_s32(q3s32, q7s32);
  q4s32 = vsubq_s32(q4s32, q8s32);

  d2s16 = vqrshrn_n_s32(q1s32, 14);
  d3s16 = vqrshrn_n_s32(q2s32, 14);
  d24s16 = vqrshrn_n_s32(q12s32, 14);
  d25s16 = vqrshrn_n_s32(q15s32, 14);
  d6s16 = vqrshrn_n_s32(q3s32, 14);
  d7s16 = vqrshrn_n_s32(q4s32, 14);
  *q12s16 = vcombine_s16(d24s16, d25s16);

  d0s16 = vdup_n_s16((int16_t)cospi_10_64);
  d1s16 = vdup_n_s16((int16_t)cospi_22_64);
  q4s32 = vmull_s16(d26s16, d0s16);
  q5s32 = vmull_s16(d27s16, d0s16);
  q2s32 = vmull_s16(d26s16, d1s16);
  q6s32 = vmull_s16(d27s16, d1s16);

  d30s16 = vdup_n_s16((int16_t)cospi_26_64);
  d31s16 = vdup_n_s16((int16_t)cospi_6_64);

  q4s32 = vmlal_s16(q4s32, d20s16, d1s16);
  q5s32 = vmlal_s16(q5s32, d21s16, d1s16);
  q2s32 = vmlsl_s16(q2s32, d20s16, d0s16);
  q6s32 = vmlsl_s16(q6s32, d21s16, d0s16);

  q0s32 = vmull_s16(d18s16, d30s16);
  q13s32 = vmull_s16(d19s16, d30s16);

  q0s32 = vmlal_s16(q0s32, d28s16, d31s16);
  q13s32 = vmlal_s16(q13s32, d29s16, d31s16);

  q10s32 = vmull_s16(d18s16, d31s16);
  q9s32 = vmull_s16(d19s16, d31s16);

  q10s32 = vmlsl_s16(q10s32, d28s16, d30s16);
  q9s32 = vmlsl_s16(q9s32, d29s16, d30s16);

  q14s32 = vaddq_s32(q2s32, q10s32);
  q15s32 = vaddq_s32(q6s32, q9s32);
  q2s32 = vsubq_s32(q2s32, q10s32);
  q6s32 = vsubq_s32(q6s32, q9s32);

  d28s16 = vqrshrn_n_s32(q14s32, 14);
  d29s16 = vqrshrn_n_s32(q15s32, 14);
  d4s16 = vqrshrn_n_s32(q2s32, 14);
  d5s16 = vqrshrn_n_s32(q6s32, 14);
  *q14s16 = vcombine_s16(d28s16, d29s16);

  q9s32 = vaddq_s32(q4s32, q0s32);
  q10s32 = vaddq_s32(q5s32, q13s32);
  q4s32 = vsubq_s32(q4s32, q0s32);
  q5s32 = vsubq_s32(q5s32, q13s32);

  d30s16 = vdup_n_s16((int16_t)cospi_8_64);
  d31s16 = vdup_n_s16((int16_t)cospi_24_64);

  d18s16 = vqrshrn_n_s32(q9s32, 14);
  d19s16 = vqrshrn_n_s32(q10s32, 14);
  d8s16 = vqrshrn_n_s32(q4s32, 14);
  d9s16 = vqrshrn_n_s32(q5s32, 14);
  *q9s16 = vcombine_s16(d18s16, d19s16);

  q5s32 = vmull_s16(d2s16, d30s16);
  q6s32 = vmull_s16(d3s16, d30s16);
  q7s32 = vmull_s16(d2s16, d31s16);
  q0s32 = vmull_s16(d3s16, d31s16);

  q5s32 = vmlal_s16(q5s32, d6s16, d31s16);
  q6s32 = vmlal_s16(q6s32, d7s16, d31s16);
  q7s32 = vmlsl_s16(q7s32, d6s16, d30s16);
  q0s32 = vmlsl_s16(q0s32, d7s16, d30s16);

  q1s32 = vmull_s16(d4s16, d30s16);
  q3s32 = vmull_s16(d5s16, d30s16);
  q10s32 = vmull_s16(d4s16, d31s16);
  q2s32 = vmull_s16(d5s16, d31s16);

  q1s32 = vmlsl_s16(q1s32, d8s16, d31s16);
  q3s32 = vmlsl_s16(q3s32, d9s16, d31s16);
  q10s32 = vmlal_s16(q10s32, d8s16, d30s16);
  q2s32 = vmlal_s16(q2s32, d9s16, d30s16);

  *q8s16 = vaddq_s16(*q11s16, *q9s16);
  *q11s16 = vsubq_s16(*q11s16, *q9s16);
  q4s16 = vaddq_s16(*q12s16, *q14s16);
  *q12s16 = vsubq_s16(*q12s16, *q14s16);

  q14s32 = vaddq_s32(q5s32, q1s32);
  q15s32 = vaddq_s32(q6s32, q3s32);
  q5s32 = vsubq_s32(q5s32, q1s32);
  q6s32 = vsubq_s32(q6s32, q3s32);

  d18s16 = vqrshrn_n_s32(q14s32, 14);
  d19s16 = vqrshrn_n_s32(q15s32, 14);
  d10s16 = vqrshrn_n_s32(q5s32, 14);
  d11s16 = vqrshrn_n_s32(q6s32, 14);
  *q9s16 = vcombine_s16(d18s16, d19s16);

  q1s32 = vaddq_s32(q7s32, q10s32);
  q3s32 = vaddq_s32(q0s32, q2s32);
  q7s32 = vsubq_s32(q7s32, q10s32);
  q0s32 = vsubq_s32(q0s32, q2s32);

  d28s16 = vqrshrn_n_s32(q1s32, 14);
  d29s16 = vqrshrn_n_s32(q3s32, 14);
  d14s16 = vqrshrn_n_s32(q7s32, 14);
  d15s16 = vqrshrn_n_s32(q0s32, 14);
  *q14s16 = vcombine_s16(d28s16, d29s16);

  d30s16 = vdup_n_s16((int16_t)cospi_16_64);

  d22s16 = vget_low_s16(*q11s16);
  d23s16 = vget_high_s16(*q11s16);
  q2s32 = vmull_s16(d22s16, d30s16);
  q3s32 = vmull_s16(d23s16, d30s16);
  q13s32 = vmull_s16(d22s16, d30s16);
  q1s32 = vmull_s16(d23s16, d30s16);

  d24s16 = vget_low_s16(*q12s16);
  d25s16 = vget_high_s16(*q12s16);
  q2s32 = vmlal_s16(q2s32, d24s16, d30s16);
  q3s32 = vmlal_s16(q3s32, d25s16, d30s16);
  q13s32 = vmlsl_s16(q13s32, d24s16, d30s16);
  q1s32 = vmlsl_s16(q1s32, d25s16, d30s16);

  d4s16 = vqrshrn_n_s32(q2s32, 14);
  d5s16 = vqrshrn_n_s32(q3s32, 14);
  d24s16 = vqrshrn_n_s32(q13s32, 14);
  d25s16 = vqrshrn_n_s32(q1s32, 14);
  q2s16 = vcombine_s16(d4s16, d5s16);
  *q12s16 = vcombine_s16(d24s16, d25s16);

  q13s32 = vmull_s16(d10s16, d30s16);
  q1s32 = vmull_s16(d11s16, d30s16);
  q11s32 = vmull_s16(d10s16, d30s16);
  q0s32 = vmull_s16(d11s16, d30s16);

  q13s32 = vmlal_s16(q13s32, d14s16, d30s16);
  q1s32 = vmlal_s16(q1s32, d15s16, d30s16);
  q11s32 = vmlsl_s16(q11s32, d14s16, d30s16);
  q0s32 = vmlsl_s16(q0s32, d15s16, d30s16);

  d20s16 = vqrshrn_n_s32(q13s32, 14);
  d21s16 = vqrshrn_n_s32(q1s32, 14);
  d12s16 = vqrshrn_n_s32(q11s32, 14);
  d13s16 = vqrshrn_n_s32(q0s32, 14);
  *q10s16 = vcombine_s16(d20s16, d21s16);
  q6s16 = vcombine_s16(d12s16, d13s16);

  q5s16 = vdupq_n_s16(0);

  *q9s16 = vsubq_s16(q5s16, *q9s16);
  *q11s16 = vsubq_s16(q5s16, q2s16);
  *q13s16 = vsubq_s16(q5s16, q6s16);
  *q15s16 = vsubq_s16(q5s16, q4s16);
  return;
}

void av1_iht8x8_64_add_neon(const tran_low_t *input, uint8_t *dest,
                            int dest_stride, const TxfmParam *txfm_param) {
  int i;
  uint8_t *d1, *d2;
  uint8x8_t d0u8, d1u8, d2u8, d3u8;
  uint64x1_t d0u64, d1u64, d2u64, d3u64;
  int16x8_t q8s16, q9s16, q10s16, q11s16, q12s16, q13s16, q14s16, q15s16;
  uint16x8_t q8u16, q9u16, q10u16, q11u16;

  q8s16 = vld1q_s16(input);
  q9s16 = vld1q_s16(input + 8);
  q10s16 = vld1q_s16(input + 8 * 2);
  q11s16 = vld1q_s16(input + 8 * 3);
  q12s16 = vld1q_s16(input + 8 * 4);
  q13s16 = vld1q_s16(input + 8 * 5);
  q14s16 = vld1q_s16(input + 8 * 6);
  q15s16 = vld1q_s16(input + 8 * 7);

  TRANSPOSE8X8(&q8s16, &q9s16, &q10s16, &q11s16, &q12s16, &q13s16, &q14s16,
               &q15s16);

  const TX_TYPE tx_type = txfm_param->tx_type;
  switch (tx_type) {
    case DCT_DCT:  // idct_idct is not supported. Fall back to C
      av1_iht8x8_64_add_c(input, dest, dest_stride, txfm_param);
      return;
      break;
    case ADST_DCT:  // iadst_idct
      // generate IDCT constants
      // GENERATE_IDCT_CONSTANTS

      // first transform rows
      IDCT8x8_1D(&q8s16, &q9s16, &q10s16, &q11s16, &q12s16, &q13s16, &q14s16,
                 &q15s16);

      // transpose the matrix
      TRANSPOSE8X8(&q8s16, &q9s16, &q10s16, &q11s16, &q12s16, &q13s16, &q14s16,
                   &q15s16);

      // generate IADST constants
      // GENERATE_IADST_CONSTANTS

      // then transform columns
      IADST8X8_1D(&q8s16, &q9s16, &q10s16, &q11s16, &q12s16, &q13s16, &q14s16,
                  &q15s16);
      break;
    case DCT_ADST:  // idct_iadst
      // generate IADST constants
      // GENERATE_IADST_CONSTANTS

      // first transform rows
      IADST8X8_1D(&q8s16, &q9s16, &q10s16, &q11s16, &q12s16, &q13s16, &q14s16,
                  &q15s16);

      // transpose the matrix
      TRANSPOSE8X8(&q8s16, &q9s16, &q10s16, &q11s16, &q12s16, &q13s16, &q14s16,
                   &q15s16);

      // generate IDCT constants
      // GENERATE_IDCT_CONSTANTS

      // then transform columns
      IDCT8x8_1D(&q8s16, &q9s16, &q10s16, &q11s16, &q12s16, &q13s16, &q14s16,
                 &q15s16);
      break;
    case ADST_ADST:  // iadst_iadst
      // generate IADST constants
      // GENERATE_IADST_CONSTANTS

      // first transform rows
      IADST8X8_1D(&q8s16, &q9s16, &q10s16, &q11s16, &q12s16, &q13s16, &q14s16,
                  &q15s16);

      // transpose the matrix
      TRANSPOSE8X8(&q8s16, &q9s16, &q10s16, &q11s16, &q12s16, &q13s16, &q14s16,
                   &q15s16);

      // then transform columns
      IADST8X8_1D(&q8s16, &q9s16, &q10s16, &q11s16, &q12s16, &q13s16, &q14s16,
                  &q15s16);
      break;
    default:  // iadst_idct
      assert(0);
      break;
  }

  q8s16 = vrshrq_n_s16(q8s16, 5);
  q9s16 = vrshrq_n_s16(q9s16, 5);
  q10s16 = vrshrq_n_s16(q10s16, 5);
  q11s16 = vrshrq_n_s16(q11s16, 5);
  q12s16 = vrshrq_n_s16(q12s16, 5);
  q13s16 = vrshrq_n_s16(q13s16, 5);
  q14s16 = vrshrq_n_s16(q14s16, 5);
  q15s16 = vrshrq_n_s16(q15s16, 5);

  for (d1 = d2 = dest, i = 0; i < 2; i++) {
    if (i != 0) {
      q8s16 = q12s16;
      q9s16 = q13s16;
      q10s16 = q14s16;
      q11s16 = q15s16;
    }

    d0u64 = vld1_u64((uint64_t *)d1);
    d1 += dest_stride;
    d1u64 = vld1_u64((uint64_t *)d1);
    d1 += dest_stride;
    d2u64 = vld1_u64((uint64_t *)d1);
    d1 += dest_stride;
    d3u64 = vld1_u64((uint64_t *)d1);
    d1 += dest_stride;

    q8u16 = vaddw_u8(vreinterpretq_u16_s16(q8s16), vreinterpret_u8_u64(d0u64));
    q9u16 = vaddw_u8(vreinterpretq_u16_s16(q9s16), vreinterpret_u8_u64(d1u64));
    q10u16 =
        vaddw_u8(vreinterpretq_u16_s16(q10s16), vreinterpret_u8_u64(d2u64));
    q11u16 =
        vaddw_u8(vreinterpretq_u16_s16(q11s16), vreinterpret_u8_u64(d3u64));

    d0u8 = vqmovun_s16(vreinterpretq_s16_u16(q8u16));
    d1u8 = vqmovun_s16(vreinterpretq_s16_u16(q9u16));
    d2u8 = vqmovun_s16(vreinterpretq_s16_u16(q10u16));
    d3u8 = vqmovun_s16(vreinterpretq_s16_u16(q11u16));

    vst1_u64((uint64_t *)d2, vreinterpret_u64_u8(d0u8));
    d2 += dest_stride;
    vst1_u64((uint64_t *)d2, vreinterpret_u64_u8(d1u8));
    d2 += dest_stride;
    vst1_u64((uint64_t *)d2, vreinterpret_u64_u8(d2u8));
    d2 += dest_stride;
    vst1_u64((uint64_t *)d2, vreinterpret_u64_u8(d3u8));
    d2 += dest_stride;
  }
  return;
}